1. Field of the Invention
The present invention relates to a hinge for eyeglasses having a structure in which the outer side of a bracket and a temple section which are component elements of eyeglasses can be opened further outward than in a state where they normally form the same plane.
2. Description of the Prior Art
It is known in the art to provide a spring hinge for eyeglasses where the temple sections fit elastically to the sides of a face of a person who wears eyeglasses. For example, Japanese Patent Publication No. Hei 6-64264 discloses a structure where the temple section does not rotate round a hinge axis, but at a portion serving as a fulcrum where the temple section and the bracket contact when the temple section is opened further outward than in the state where the outer side of the bracket and the temple section are in the same plane. In this structure, a hinge unit forming the hinge is arranged to slide onto the temple section when the temple section is opened outward relative to the bracket.
Further, in the hinge for eyeglasses adapted to elastically fit the temple sections to the sides of the face of the person who wears the eyeglasses as described above, Japanese Utility Model Application Open-Publication No. Sho. 64-3820 discloses a simple structure in which the temple section is moved to rotate both outward and inward by penetratingly rotating a flat portion of the bracket relative to a side groove which opens to the outside of the temple section.
However, in the conventional hinge, Japanese Patent Publication No. Hei 6-64264 discloses the structure where dovetail groove working is required to cause the hinge unit to slide surely onto the temple section. Therefore, the manufacturing cost is high. Further, since the dovetail groove or complicated working is required in a narrow section of the small parts of the eyeglasses, the mechanical strength for the eyeglasses as a whole and at the hinge part thereof becomes a problem.
Also, the hinge disclosed in Japanese Utility Model Application Open-Publication No. Sho. 64-3820 has an advantage in its simple structure, but there are some appearance and design problems as shown below: A side groove of the hinge portion is exposed to affect a sense of unity as a whole which is an important factor for a design of eyeglasses. In addition, the flat portion of the bracket protrudes in a folding condition of the temple section when the eyeglasses are not used and this is another design problem to be solved.